What is plagiarism?
Is using ideas and/or words from a different person, claiming as ones own without proper credit to the real source (Merriam-Webster Dictionary).
The inability to give credit and acknowledge ideas or phrases used in any paper, publication, or project submitted but gained from another person (http://english.la.psu.edu).
What are the different types of plagiarism?
1. Word-for-word Plagiarizing happen when you try to change opening part of the sentence, so that the readers wont notice that the remaining of the entire paragraph is just a copy from the source (http://academics.hamilton.edu).
2. Plagiarizing by paraphrase the same concept from the source are being followed in a close manner simply by just substituting and changing some words with your own words and sentenced for those of the original text (http://academics.hamilton.edu).
3. The Source The writer should have proper citation about the source, it should be clear and exact.
4. Mosaic Plagiarism this is more complicated type of plagiarism, because phrases and words are actually from the source or original text and you just add some of your words (http://academics.hamilton.edu).
5. Summary using quotation marks during an oral presentation and while writing a paper can help avoid plagiarism, but when overdone it will look like a patchwork and will resemble the original (Types of Plagiarism, http://la.psu.edu). If it happened that almost the entire thing that you want to say came from one source, directly quote or paraphrase it so it will look better. But either way, introduce your borrowed words or ideas by pointing out that those ideas are from the author and followed them with citation inside the parenthesis (Types of Plagiarism, http://la.psu.edu).
How do we avoid them in oral presentation?
Consider indicating direct quotation, by saying quote and follow it with unquote or close quote.
Another approach is by saying: In her 1998 owners guide, Airedale Terriers, trainer Dorothy Miner says the following about the origins of the Airedale Terrier.
If you are citing a saying from anonymous sources, you can say It is always said that¦
In oral presentation usually the citation is trimmed down to just the author, Title of the publication date and title.
With all these information regarding plagiarism and proper citation I am sure it will be a big help for you to start so to speak. But with constant practice and proper usage of voice, using proper intonation, correct stress on words, pronunciation and enunciation you can become one of the most effective communicator.